void tut12(){
  TCanvas *c1 = new TCanvas();

  TF1 *func=new TF1("func","exp(-[1]*x)*[0]*sin(x)",0,10*TMath::Pi());

  func->SetTitle("");

  func->SetParameter(0,1);
  func->SetParameter(1,0.1);
  
  func->Draw();
}
